I just got off the phone with Canon support, and as of TODAY they finally have a statement they can give to 1d3 owners who call in about the focusing issue.

THEY HAVE IDENTIFIED A FIX, AND IT IS NOT FIRMWARE. IT'S A "SUBMIRROR ASSEMBLY" THAT MUST BE REPLACED.

Personally I suspected all along it would be a physical item, as firmware can't explain the success variation reported by users here.

The support rep, who I shall leave unnamed, said they are to start collecting names of owners to contact, in addition to going off of existing registration data (Personally, mine was not officially registered) to set up RMA's for resolution (I will obviously register at some point to get the $100 certificate, I know, I know... ).

He was helpful in taking my info, and if you have not already registered, you might want to do so or call in yourself to be sure you are contacted. They support guys have had to suffer almost as much as us, so be nice to them!

Also, he told me that latest production running off the line has been corrected.